Physical properties of photographic papers



United States Patent M 2,970,907 PHYSICAL PROPERTIES OF PHOTOGRAPHIC PAPERS Joseph Sottysiak, Binghamton, and Benjamin R. Harriman, Rochester, N.'Y., assignors to Genera} Aniline 8: Film Corporation, New York, N.Y., a corporation of Delaware No Drawing. Filed Apr. 20, 1956, Ser. No. 579,433 8 Claims. or. 96-85) The'present invention relates to protective layers for photographic silver halide emulsion layers, particularly anti-abrasion protective layers especially for photographic papers. Photographic papers, usually the so-called glossy types, are generally provided with a protective overcoat-' quence, the ferrotyped prints frequently exhibit a tow gloss caused by these and other factors. Close examination establishes the low gloss and ferrotyping imperfections to, be attributable to defects own as pits, edge lift and oyster shells.

Edge lift, as is known in the art, means the dullness at the edges of the prints caused by insufficient length of contact between the edges of the print and the polished metal surface. Oyster shells, on the other hand, refer to the concentric circles in prints occasioned by improper drying.

Bower et al., in their U.S. Patent 2,633,423, suggested that these-defects might be cured by substituting for the conventional gelatin overcoat a layer of a hydantoin-formaldehyde resin. it is claimed that such resin coatings not only impart anti-abrasion properties to the gelatino-silver halide layer but also give smoother surfaces, less warping and a better over-all appearance to the finished product, particularly photographic paper.

It has also been suggested'that poor ferrotyping can be obviated or suppressed by careful operation in processing. It has been found, however, that this procedure materially slows up the operation while requiring the use of additional chemicals and techniques.

It has now been discovered that the problems mentioned with respect to ferrotyping, particularly of photographic paper, can be overcome by overcoating the silver 1 halide emulsion layer with an anti-abrasion gelatin coating containing an anionic or non-ionic surface active agent alone or preferably with beeswax.

It is, accordingly, an object of the present invention to provide an anti-abrasion layer on photographic paper, permitting ferrotyping with high gloss when the paper is contacted with a polished metal surface.

A further object of the invention is to build into the photographic paper protection against ferrotyping deects.

A still further object of the invention is to enable the ferrotyping of prints while ensuring that the resulting gloss is free from pitting, edge lift and oyster shells.

Other and further important objects will appear as the description proceeds.

2,970,907 Patented Feb. 7, 1961 As previously stated, our invention is predicated upon the incorporation in a gelatin protective layer of a surface'active agent which is chosen for its ability to orient itself on the surface of the photographic material in such a way as to provide the desired ferrotyping characteristics. Surface active agents which meet these prerequisites are any of the anionic or non-ionic surface active agents. Surface active agents of the anionic and nonionic class are well known in industry and are available on the open'market. Examples of the anionics which we have found tobe particularly suitable are sodium tetradecyl sulfate, sodium octyl phosphate, the sodium salt of aromatic sulfonic acids such as the sodium salt of butyl naphthalene'sulfonic acid, the sodium salt of keryl benzene sulfonic acid (the product resulting from the condensation of chlorinated kerosene with benzene followed by sulfonation), monodiethylaminoethyldodecenyl succinate, U.S. Patent 2,805,948, and the like. Examples, of non-ionic surfactants are diglyocal laurate, the condensation products of compounds containing a reactive hydrogen atom with ethylene oxide such as the products described in U.S. Patent 1,970,578, specifically,

2,6,8-trimethyl nonanol-4 with 12 mols of ethylene oxide, diamyl phenol with 20 mols of ethylene oxide and the like and the condensation products of long chain fatty acids with proteins such as those described in U.S. Patent 2,015,912. Best results were secured with the succinic acid derivative and we, accordingly, prefer the use of this compound.

The efiective concentration of the surface active agent in the gelatin ranges from 2.5 to grams per kilo of gelatin and preferably from 5 to 10 grams per kilo.

It has been ascertained that, while the ferrotyping properties are materially augmented by the use of the surfactant alone, such properties are even further improved if there be incorporated into the gelatin-surfactant mixture, an addition of a beeswax emulsion. The beeswax should be of purest possible grade to ensure free dom from photographic contamination, on the one hand,

and uniformity of ferrotyping, on the other hand. Purisons which we have been unable to ascertain, gives opti-' mum results when there is used with the aforesaid components a stabilizer for silver halides, for example, those described in U.S. Patents 2,440,110; 2,440,206; 2,385,- 762; and 2,394,198. The quantity of stabilizer would be within the range stated in said patents.

The invention is further illustrated examples, it being understood, howeve tion is not restricted thereto.

by the following that the inven- Example I A 2% gelatin solution was prepared by dissolving one kilogram of gelatin in distilled water. This gelatin solution was heated to 30 C. and to it were added 300 mls. of 10% chrome alum solution, a silver halide stabilizer (of the type and in the quantity mentioned in U.S. Patent 2,440,110) and 7.5 grams of monodiethylaminoethyldodecenyl succinate. In a separate container, 125 grams of beeswax and 6.3 mls. of triethanolamine were heated to 65 C. and poured into 1250 mls. of water at 65 C. The resulting beeswax emulsion was cooled to 30 C. and an additional 1250 mls. of distilled water were semi-see 3 added. The 2500 mls. of wax emulsion were added to the gelatin solution with stirring at 30 C. and the solution was coated at this temperature over a wet chilled gelatino-silver halide layer on a paper support. This protective layer dried down to a thicknessof about 1;

micron.

Thisphotographic paper was compared with asimilar paper which difieredonly, in-that the protectivelayer was made from a 2% g'elatinfsolution to which had beenf added chrome alum; the stabilizer and 100 grams of saponin. Both papers were exposed, processed in the normal manner and then, after washing, placed emulsion side down upon a cold polished metal surface for simul"- taneous drying,and'ferrotyping. The paper with' the pro-.

that the beeswax emulsion is omitted. The paper with the; protective layer containing the. mono'diaminoethyL dodecenyl'j succin'ate had far better resistance toward physical defe'ct sithan a' s'imilar paper in whichfthe protec tive layerisi'fr'e'e from such surfactant Exqmple III The procedure is} the same as in Example 1, excepting that the paper was; ferrotyped upon a hot polished metal plate. The: improvements noted in Example'l were also observed-in this instance. i

Example IV The. procedure is the same as' in Example ILPXCfipii-llg' that, th' paper was' f rrotyp t upon ,a hot polished metal 35 fecjts was agairrv'ohser'v Modification of' tl'r finvention will occur to, personsskilled in the art and we, therefore, do not intend to be. limited in. the patent granted except as 1 necessitated by.

the appended claimsl' We .claim: i

1'. Light-sensitive photographic paper having. excellent f'errotypihg characteristics comprising a paper base coated with a gelatino" silver halide emulsion which, in turn, is overcoated with a thin layer] ofgelatin having dispersed:

4 therethrough as the sole surfactant a surface activeagent selected" from the class consisting of monodiethylaminocthyldodecenyl succinate, the condensation product of 2,6,8-trimethylnonanol-4 with ethylene oxide and the condensation product of diarnylphenol with ethylene oxide.

2,,The articlerastdefined in claim 1, wherein thegelatin overcoat contains beeswaxlin a'n amount ranging from to 400 grams per kilo of gelatin.

3. Light-sensitive photographic-paper having excell'ent ferrotyping characteristics, comprising a base coated with agelatino-silver halide emulsion which is, in turn, overcoated with a thin layer of gelatin having dispersed therethrough as the sole surfactant a surface active agent selected from the group consisting of monodiethylamino- 'dodecenyl succina'te, the condensation product of 2,6,8-

face active agent is monodiethylaminoethyldodecenyl succinate.

"7". 'Iilie article. definedin. cl .2, wliereintthe. surface, activ,

;m i fl sil eelifleflhY siod s y elim nate: The, art cle asidefined: in claim. 3, wherein the; sur;

ate

' References Gited-in th'ejfile of' this patent} Q EQ STATE I AIEN S? 2,368,287 Chilton Jan; 30, 1945 2,440,110, Mueller Apr. 20, 1948 2,465,149; Dersch. et. al. -7 Mar; 22, 1949 2,600,831: Baldsiefen June 17, 1952' 2 ,719,087 Knox-t et al. -2 Sept. 2 7 1955-. 2,726,955: Parnell D ec. 13, 19-55 FOREIGN PATENTS 4li973 fi sat-B i ia-a r o 5; 19%;,

lse c i sset s net iy mia h de weave 

1. LIGHT-SENSITIVE PHOTOGRAPHIC PAPER HAVING EXCELLENT FERROTYPING CHARACTERISTICS COMPRISING A PAPER BASE COATED WITH A GELATINO SILVER HALIDE EMULSION WHICH, IN TURN, IS OVERCOATED WITH A THIN LAYER OF GELATIN HAVING DISPERSED THERETHROUGH AS THE SOLE SURFACTANT A SURFACE ACTIVE AGENT SELECTED FROM THE CLASS CONSISTING OF MONODIETHYLAMINOETHYLDODECENYL SUCCINATE, THE CONDENSATION PRODUCT OF 2,6,8-TRIMETHYLNONANOL-4 WITH ETHYLENE OXIDE AND THE CONDENSATION PRODUCT OF DIAMYLPHENOL WITH ETHYLENE OXIDE.
 3. LIGHT-SENSITIVE PHOTOGRAPHIC PAPER HAVING EXCELLENT FERROTYPING CHARACTERISTICS, COMPRISING A BASE COATED WITH A GELATINO SILVER HALIDE EMULSION WHICH IS, IN TURN, OVERCOATED WITH A THIN LAYER OF GELATIN HAVING DISPERSED THERETHROUGH AS THE SOLE SURGACTANT A SURFACE ACTIVE AGENT SELECTED FROM THE GROUP CONSISTING OF MONDIETHYLAMINODODECENYL SUCCINATE, THE CONDENSATION PRODUCT OF 2,6,8TRIMETHYLNONANOL-4 WITH 12 MOLS OF ETHYLENE OXIDE AND THE CONDENSATION PRODUCT OF DIAMYLPHENOL WITH 20 MOLS OF ETHYLENE OXIDE, A STABILIZING AMOUNT OF A STABILIZER FOR SIVER HALIDES, AND BESSWAX. 